The present invention relates generally to railroad vehicles and, in particular, to a method and apparatus for testing and monitoring railroad vehicle brakes.
Monitoring systems have been utilized with many devices such as for the control of air conditioning appliances and of doors, as well as for protection against skidding and the detection of flat spots on vehicle wheels, and for railroad trains. U.S. Pat. No. 4,781,622 discloses a central fault indicating system for a railroad train in which nine different functions are indicated by centrally arranged signal lamps for a maximum of fifteen cars. A functional relay system on each individual car is interrogated periodically and the failure of a function in one or more cars is indicated by lighting the associated signal lamp in the lead car. For the brakes, the release and pulling-up movement is acknowledge. Through the arrangement of one hundred thirty-five (nine functions times fifteen cars) signal lamps in the lead car, a coarse localization of a failed function is possible when a breakdown occurs. The system utilizes standard hardware and known digital communication techniques. However, it is not possible to exercise active and differentiated control of the test functions from the central location in the lead car. Only a single digit measurement magnitude without qualitative content is present for each function and the self-test is restricted to the testing of the signal lamps. A diagnostic function is not present and individual cars which are detached from the train cannot be tested.